Datasheet

MAX187/MAX189
+5V, Low-Power, 12-Bit Serial ADCs
6Maxim Integrated
Pin Description
Pin Configurations
PIN
NAME FUNCTION
PDIP WIDE SO
1 1 V
DD
Supply Voltage. +5V, Q5%
2 3 AIN Sampling Analog Input. 0V to V
REF
range
3 6 SHDN
Three-Level Shutdown Input. Pulling SHDN low shuts the MAX187/MAX189 down to 10FA
(max) supply current. Both MAX187 and MAX189 are fully operational with either SHDN
high or unconnected. For the MAX187, pulling SHDN high enables the internal reference,
and letting SHDN unconnected disables the internal reference and allows for the use of an
external reference.
4 8 REF
Reference Voltage—sets analog voltage range and functions as a 4.096V output for the
MAX187 with enabled internal reference. REF also serves as a +2.5V to V
DD
input for a
precision reference for both MAX187 (disabled internal reference) and MAX189. Bypass
with 4.7FF if internal reference is used, and with 0.1FF if an external reference is applied.
5 — GND Analog and Digital Ground
— 10 AGND Analog Ground
— 11 DGND Digital Ground
6 12 DOUT Serial Data Output. Data changes state at SCLK’s falling edge.
7 15 CS
Active-Low Chip Select. Initiates conversions on the falling edge. When CS is high, DOUT is
high impedance.
8 16 SCLK Serial Clock Input. Clocks data out with rates up to 5MHz.
—
2, 4, 5, 7,
9, 13. 14
N.C. No Connection. Not internally connected. Connect to AGND for best noise performance.
REF GND
1
2
8
7
V
DD
AIN
DOUT
SCLK
PDIP
TOP VIEW
3
4
6
5
MAX187
MAX189
MAX187
MAX189
SHDN
CS
+
N.C.
N.C.N.C.
1
2
16
15
SCLK
+
CSN.C.
AIN
V
DD
Wide SO
3
4
14
13
DGND
AGNDN.C.
512 DOUTN.C.
SHDN 6
7
11
10
N.C.REF 89